Letter feeder,synchronous friction type

ABSTRACT

A SYNCHRONOUS-TYPE APPARATUS FOR FEEDING LETTER MAIL OF VARIOUS SIZES AND THICKNESS. A FEED WHEEL AND A STRIPPER WHEEL ARE POSITIONED IN OPPOSED RELATION AT A FEED AREA IN THE APPARATUS TO RECEIVE THEREBETWEEN LETTERS WHICH ARE TO BE SINGULATED AND FED TO A PROCESSING UNIT. AN ELASTOMERIC MEMBER IS WRAPPED AROUND A SECTOR OF THE FEED WHEEL TO ENGAGE THE LETTERS ALONG A LINE PARALLEL TO THE LONG DIMENSION OF THE LETTERS. THE FEED WHEEL IS ROTATED AT VARYING ANGULAR VELOCITIES, SO THAT THE LEADING PORTION OF THE ELASTOMERIC MEMBER ENGAGES A LETTER TO BE FED AT A LOW VELOCITY, AND THE TRAILING PORTION OF THE ELASTOMERIC MEMBER DISCHARGES THE LETTER AT A HIGHER VELOCITY. THE LOW VELOCITY AT ENGAGEMENT REDUCES THE &#34;SCRUBBING&#34; ACTION ON THE LETTERS BEING FED AND REDUCES WEAR ON THE FEED AND STRIPPER WHEEELS.

8 1972 H. w. WEEKS ETA!- 3,664,661

LETTER FEEDER, SINCH RONOUS FRICTION TYPE Filed Sept. 4, 1970 v 2 Sheets-Sheet 1 INVENTORS HORACE W. WEEKSE May 23, 1972 H. w. WEEKS EFAL 3,664,661

LETTER FEEDER, SYNCHRONOUS FRICTION TYPE 2 Sheets-Sheet 2 Filed Sept.

FIG.2

INVENTORS HORACE W. WEEKS 8- J0 R. FRAZlEF/(/L W a HEIR ATTORNEY United States Patent O1 fice 3,664,661 Patented May 23, 1972 Int. Cl. B65h 3/06 US. Cl. 271-36 3 Claims ABSTRACT OF THE DISCLOSURE A synchronous-type apparatus for feeding letter mail of various sizes and thicknesses. A feed wheel and a stripper wheel are positioned in opposed relation at a feed area 1n the apparatus to receive therebe-tween letters which are to be singulated and fed to a processing unit. An elastomeric member is wrapped around a sector of the feed wheel to engage the letters along a line parallel to the long dimension of the letters. The feed wheel is rotated at varying angular velocities, so that the leading portion of the elastomeric member engages a letter to be fed at a low velocity, and the trailing portion of the elastomeric member discharges the letter at a higher velocity. The low velocity at engagement reduces the scrubbing action on the letters being fed and reduces wear on the feed and stripper wheels.

This invention was developed under a contract with the United States Post Office.

BACKGROUND OF THE INVENTION This invention relates to an apparatus of the synchronous type for singulating and feeding media, like letters, one at a time from a stack to a utilization device, like a coding device or a letter sorter.

While this invention may be used for handling media like cards, sheets, envelopes, and the like, it seems appropriate to describe it in relation to the processing of mail.

A basic mechanism used in mechine handling of mail is a feeding device. The feeding device is used to feed letters which are generally stacked on a long edge to a utilization device like a coding device or a cancelling machine. One of the basic requirements of a feeding device is that it singulate the letters and feed them one at a time to a utilization device. It is also necessary that the feeding device be capable of handling a variety of letter sizes and thicknesses.

Some prior-art feeding devices are shown in the following US. patents: 2,368,519-Burckhardt et al., Jan. 30, 1945 2,762,623Uthenwoldt et al., Sept. 11, 1956 2,887,951--Strother et al., May 26, 1959 2,926,910-Martin, Mar. 1, 1960 2,970,834-Martin et al. Feb. 7, 1961 Some of the advantages of the present invention over the prior-art friction-type letter feeders are as follows:

The present invention:

(1) Reduces scrubbing on the face of the media being fed. (2) Reduces wear on the parts of the device which come nous type for singulating letters and feeding them, one at a time, from a stack to a utilization device. The letters are stacked with the long edges positioned horizontally and are fed to a feed area, where a feed wheel means and stripper wheel means are positioned in opposed relation to receive therebetween the letters and to discharge them one at a time to the utilization device. The feed wheel means includes a feed wheel, which is mounted in a frame means for rotation in a horizontal plane and has an elastomeric member mounted around a portion of the periphery of the feed wheel, so that the elastomeric member engages the letters along a line which is parallel to the long edges of the letters. A drive means rotates the feed wheel at varying angular velocities, so that, when the elastomeric member first contacts a letter to be fed, it is travelling at a low velocity, and, by the time the letter is discharged by the elastomeric member, it is travelling at a high velocity. The stripper wheel means includes a stripper wheel which is mounted in the frame means for rotation in a horizontal plane and is rotated at a constant velocity in a direction opposite to the direction of rotation of the feed wheel. The stripper wheel is mounted on a spring-loaded pivot arm to facilitate the handling of letters of varying thicknesses.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the feeding apparatus of this invention showing the leading edge of a letter entering a feed area where a feeder wheel means and stripper wheel means are placed in opposed relation.

FIG. 2 is a plan view similar to FIG. 1 showing a letter about to leave the feed area and enter a receiving means.

FIG. 3 is a side elevational view taken along the line 3-3 of FIG. 2 showing details of a drive means for rotat ing a feeder wheel of the feeder wheel means.

FIG. 4 is a front elevational view of a universal-type coupling used to drive the stripper wheel means.

F IG. 5 is a side elevational view of the coupling shown in FIG. 4 and is taken from the direction marked A in FIG. 4.

BRIEF DESCRIPTION OF THE INVENTION FIG. 1 is a plan view of the feeding apparatus of this invention. In general, the apparatus includes an input means 10, a feed area 12, a feed wheel means 14, which is placed in opposed relation with a stripper wheel means 16, and a receiving means 18.

The input means .10 (FIG. 1) includes a flat horizontal area or table 20 having a rectangular opening 22 therein. An endless belt 24, travelling in the direction indicated by the arrow 26, is positioned near the opening 22, so that its upper moving surface extends into the opening 22 to move a stack of letters towards a feed fence 27. The feed fence 27 is a vertical wall which is arcuately shaped near the entrance to the feed area 12, as shown in FIG. 1. As the belt 24 moves, it tends to align one edge (the leading edge) of the letters against the feed fence 27. The moving belt 24 has a center line, which is positioned at an angle a (FIG. 1) of about five degrees relative to a guide bar 28. The belt 24 also assists in moving the letter towards the guide bar 28 due to the angle at which the center line of the belt 24 is positioned relative to the guide bar 28. The letters (only one, marked 30, being shown in FIG. 1) are stacked vertically, with their long edges positioned horizontally, and are also assisted in their movement towards the bar 28 by a spring-loaded arm 32. The arm 32 has one end fixed to a bushing 34, which is slidably mounted on a bar 36, which is suitably fixed to the table 20. -A conventional constant-tension spring unit 38, whose extensible member 40 is secured to the arm 32, is used to maintain a constant tension on the stack of letters to move them towards the bar 28.

The input means (FIG. 1) also includes an endless belt 42, which is used to feed the letters to the feed area 12. The endless belt 42 is mounted on two rollers 44 and 46, which are rotated at uniform velocity in the direction of the arrows 48 by conventional drive means (not shown). The guide bar 28 has a suitable slot therein to permit the belt 42 to pass through the bar 2 8 and engage the letter immediately adjacent to the bar 28 and move the letter 30 to the left (as viewed in FIG. 1) to the feed area -12. A letter 30 is shown in the process of entering the feed area 12 in FIG. 1. This letter 30 is positioned on its long edge and is viewed from above, so that its thickness is shown in FIG. 1.

As the letter 30 enters the feed area 12 (FIG. 1), it is engaged by the feed wheel means 14 and the stripper wheel means 16. The feed wheel means 14 includes a feed wheel 52, which is fixed to a vertically-aligned shaft 54. The shaft 54 is rotatably mounted in a conventional bearing unit 56 (shown in FIG. 3), which is secured to the flat area or table 20 by fasteners 58. The shaft 54 is restrained against axial movement by a shoulder 60 thereon, which abuts against the upper bearing 62 (FIG. 3) of the unit 56 and a bushing 64. The bushing 64 is rotatably mounted on the shaft 54 and is positioned between the lower bearing 66 of the unit 56 and a guide block 68. The shaft 54 is fixed to rotate with the guide block 68 by a set screw 70. A suitable hole 72 in the table 20 provides clearance for the bushing 64. The guide block 68 has a radially-aligned slot 74 therein, as shown, into which a cam roller 76 is positioned. The cam roller 76 is rotatably supported on a shaft 78 perpendicularly upstanding from a crank arm 80, as shown in FIG. 3, and the crank arm is driven by a shaft 82, whose axis of rotation is offset from the axis of rotation of the wheel 52 by a distance d. The shaft 82 is conventionally driven at a constant rate.

The feed wheel means 14 has a letter-engaging surface, which is constructed as follows. The wheel 52 has an arcuately-shaped rim 84 upstanding from a portion of the perimeter of the wheel, as is best shown in FIGS. 1 and 2. Two pins 86 and 88, upstanding from the feed wheel 54, are positioned near the ends of the rim 84, which has a plurality of equally-spaced, axially-aligned recesses 90 therein. A relatively thick, endless, elastomeric band 92 is wrapped around the rim 84, around the pins '86 and 88, and around a bushing 94, which is mounted on the shaft 54, as shown in FIGS. 1 and 2. The band 92 has equallyspaced, axially-aligned projections 96 positioned on the side thereof which engages the rim 84. These projections 96 extend along the axial length of the band 92 and are arcuately-shaped in cross-section, so as to fit into the recesses 90, which are complementary in shape to receive them.

The stripper wheel means 16, shown in FIGS. 1 and 2, includes a wheel 98, which is fixed to a shaft 100 to rotate therewith. The shaft 100 is rotatably mounted in an arm 102 having one end pivotally mounted on a shaft 104 secured perpendicularly to the table 20. The free end of the arm 102 is apertured at 106 to permit a stop pin 108 to pass therethrough. The pin 10 8 has an enlarged head 1 10 to act as a stop and is adjustable to control the extent to which the arm 102 will pivot counter-clockwise (as viewed in FIGS. 1 and 3) under the influence of a spring 112, whose compression can be adjusted. The shaft 100 is connected to a universal-type coupling 114, shown in FIGS. 4 and 5. The coupling 114 is commercially available and is described in U.S. Pat. No. 3,224,224, which issued Dec. 21, 1965, on the application of Peter Kudriavetz, Jr. The coupling .114 is made of flexible urethane with metallic ends for coupling to shafts and has the general shape shown. The shaft I100 is secured to one metallic end 116 of the coupling, and the other metallic end 118 is secured to a driving shaft 120', which is rotated at a constant rotational velocity by a conventional drive means (not shown). The universal-type coupling 114 is needed to handle misalignment between the shafts 1,00 and when the arm 102 moves away from the head of the stop pin 108 due to a letter 30 being fed as shown in FIG. '2. The stripper wheel is rotated clockwise (as viewed in FIGS. 1 and 2), which is a direction opposite from the direction of rotation of the feed wheel 52. The stripper wheel 98 has an elastomeric band 122 located around its periphery. The band .122 has an axial length equal to the axial length of the elastomeric band 92, shown in FIG. 3, and the center of the band 92 as measured in the axial direction, the center of the band 122 similarly measured, and the center of the belt 42 as measured in an axial direction all lie in a common plane, which is parallel to the table 20. This is important for feeding the letters 30 to avoid their skewing in a vertical plane, or, stated another way, to keep the long edges of the letters 30 horizontal as they are fed to the receiving means 18. The receiving means, designated generally as 18, is best shown in FIG. 2 and includes two endless belts 124 and 126. The belt 124 is supported on a roller 128, which is fixed to a vertically-aligned shaft 130, and the belt 126 is similarly supported on a roller 132, which is fixed to a vertically-aligned shaft 134. The rollers 128 and 132 are spaced apart from each other to provide a throat area 136 for receiving letters from the feed wheel 52. The shafts and 134 are driven at the same constant speeds by conventional means (not shown) to rotate the rollers 128 and 132 in the directions shown by the arrows there on. A third roller 138 is fixed to a shaft 140, which drives the roller 138 in the direction shown by the arrow thereon. The shaft 140 is driven at a constant velocity by conventional means (not shown). The roller 138 forces the belts 124 and 126 together, so as to sandwich a letter therebetween and transport it to a utilization device like a coder, 21 facer-canceller, etc., not shown.

The particular sizes and speeds selected for the various moving components of this invention are naturally dependent upon the particular application in which it is used. The particular application selected to portray the invention was a letter-feeding apparatus. The range of letters which this feeding apparatus can handle is:

Inches Length 4.25-1 1.5 Width 3.0-6.125 Thickness 0.0060.25

The particular relationships of the various elements of this invention are as follows. The surface speed of the belts 24 and 42 of the input means 10- is thirty inches per second. The shaft 82, which drives the feed Wheel means 14, is rotated at a constant rate of 600 revolutions per minute, and, because of the crank (78, "80) used to rotate the feed wheel 52, the feed wheels surface velocity as measured on the elastomeric band 92 will vary between about 85 inches per second and about 140 inches per second. The surface velocity of the belts 124 and 126 of the receiving means 18 is about inches per second, which is slightly higher than the maximum discharge velocity from the feed wheel 52. The clearance between the elastomeric band 92 on the feed wheel 52 when it is opposite the stripper wheel 98 is 0.004 inch. The distance between centers of the roller 138 and the feed wheel 52 is equal to or less than the minimum length of letter which is to be fed by the apparatus to avoid a free-floating letter. Because the apparatus is synchronous, only one letter will be fed for each revolution of the feed wheel 52. This rate is six hundred letters per minute. The elastomeric band 92 on the feed wheel 54 passing through the guide bar 28 cannot be longer than the minimum length of letter to be fed, and the rate at which the band 92 is exposed through the slot in the guide bar 28 is such as to provide a pitch of fourteen inches. That is, the leading edge of a letter received at the receiving means 18 follows the leading edge of the next preceding letter by fourteen inches. The coefficient of friction of the elastomeric band 92 is about four times greater than the coefficient of friction on the band 122 on the stripper wheel 98. The surface velocity of the stripper wheel 98 as measured on the band 122 is thirty inches per second and is in a direction opposite to the velocity of the elastomeric band 92 on the feed wheel 52.

By this construction, the letters are positively driven throughout the feeding apparatus. The stripper wheel means 16 prevents the passage of a letter until the elastomeric band '92 approaches it. When the band '92 engages a letter, it is travelling at a low velocity, about eightyfive inches per second, to minimize scrubbing the surface of the letter during contact. Because of the coefficient of friction of the band 92 and its velocity, the letter 30 is driven to the left (as viewed in FIG. 1), while the letters next in line to be fed are prevented from moving with the letter 30 by the stripper wheel means 16. Because the band 92 does not extend completely around the periphery of the feed wheel 52, a thick letter (like 0.25 inch thick) can easily enter the feed area 12 and can easily be accommodated by the apparatus. By the time the trailing edge of the band 92 on the feed wheel 52 engages a trailing portion of the letter 30, the letter 30 has been accelerated to a velocity of about 140 inches per second.

What is claimed is:

1. A synchronous-type feeding apparatus for feeding letters of various sizes and thicknesses to a receiving means, comprising:

a frame means;

a feed area;

input means on said frame means for feeding the letters to the feed area with a long edge of each letter positioned horizontally;

a receiving means; and

a feed wheel means and a stripper wheel means positioned in opposed relation at said feed area to receive therebetween letters from said input means and to discharge the letters singly to the receiving means; said feed wheel means comprising:

a feed wheel rotatably mounted on said frame means to rotate in a horizontal plane; an elastomeric member having leading and trailing portions and extending around a portion of the periphery of the feed wheel to engage a letter along a line parallel to the long edge of the letter and transfer it to the receiving means; and variable velocity drive means for rotating the feed Wheel so that the letters being fed thereby will be gradually accelerated from the time that the leading portion of the elastomeric member engages a letter to be fed until the time when the letter leaves the trailing portion of the elastomeric member;

said stripper wheel means including:

a stripper wheel mounted on said frame means for rotation in said horizontal plane and having a letter-engaging periphery to engage the letters being fed; and

drive means for rotating the stripper Wheel at a constant velocity in a direction opposite to the direction of rotation of the feed wheel so as to permit only one letter at a time to be fed between said elastomeric member and said stripper wheel.

2. The apparatus as claimed in claim 1 in which the variable velocity drive means for rotating the feed wheel includes:

a shaft fixed to said feed wheel;

a lever fixed to one end of said shaft to rotate said feed wheel, said lever having a radially-aligned slot therein; and

a crank member having an axis of rotation offset from the axis of rotation of said shaft and having a member adapted to fit into said slot and rotate said lever.

3. A synchronous-type feeding apparatus for feeding letters of various sizes and thicknesses to a receiving means, comprising:

a frame means;

a feed area;

input means on said frame means for feeding the letters to the feed area with a long edge of each letter positioned horizontally;

a receiving means; and

a feed wheel means and a stripper wheel means positioned in opposed relation at said feed area to receive therebetween letters from said input means and to discharge the letters singly to the receiving means;

said feed wheel means comprising:

a feed wheel rotatably mounted on said frame means to rotate in a horizontal plane;

an elastomeric member having leading and trailing portions and extending around a portion of the periphery of the feed wheel to engage a letter along a line parallel to the long edge of the letter and transfer it to the receiving means; and

variable velocity drive means for rotating the feed wheel so that the letters being fed thereby will be gradually accelerated from the time that the leading portion of the elastomeric member engages a letter to be fed until the time when the letter leaves the trailing portion of the elastomeric member;

said stripper wheel means including:

a stripper wheel mounted on said frame means for rotation in said horizontal plane and having a letter-engaging periphery to engage the letters being fed;

drive means for rotating the stripper wheel at a constant velocity in a direction opposite to the direction of rotation of the feed wheel so as to permit only one letter at a time to be fed between said elastomeric member and said stripper wheel;

a fixed stop enabling said letter-engaging periphery of the stripper wheel to be spaced a fixed distance from said elastomeric member, and

means for resiliently urging said stripper wheel towards said stop; and

means for mounting said stripper wheel to pivot towards and away from said feed wheel;

said drive means for rotating the stripper wheel including a universal coupling to accommodate the pivoting of the stripper wheel while it is rotated.

References Cited UNITED STATES PATENTS 3,173,681 3/1965 David et a1 27l34 2,845,267 7/1958 Persson 27|l-34 2,110,980 3/1938 Swift 271-35 1,986,800 1/1935 Elliott 271-41 X JOSEPH WEGBREIT, Primary Examiner US. Cl. X.R. 27l34 

